/*
* Copyright (c) 2015 NAVER Corp.
* egjs projects are licensed under the MIT license
*/
import { InputEventType, ExtendedEvent } from "../types";
import { EventInput } from "./EventInput";
export class TouchEventInput extends EventInput {
public readonly start = ["touchstart"];
public readonly move = ["touchmove"];
public readonly end = ["touchend", "touchcancel"];
private _baseTouches: TouchList;
public onEventStart(
event: InputEventType,
inputKey?: string[]
): ExtendedEvent {
this._baseTouches = (event as TouchEvent).touches;
Iif (!this._isValidEvent(event, inputKey)) {
return null;
}
return this.extendEvent(event);
}
public onEventMove(
event: InputEventType,
inputKey?: string[]
): ExtendedEvent {
Iif (!this._isValidEvent(event, inputKey)) {
return null;
}
return this.extendEvent(event);
}
public onEventEnd(event: InputEventType): void {
this._baseTouches = (event as TouchEvent).touches;
return;
}
public onRelease(): void {
this.prevEvent = null;
this._baseTouches = null;
return;
}
public getTouches(event: InputEventType): number {
return (event as TouchEvent).touches.length;
}
protected _getScale(event: TouchEvent): number {
if (event.touches.length !== 2 || this._baseTouches.length < 2) {
return null; // TODO: consider calculating non-pinch gesture scale
}
return (
this._getDistance(event.touches[0], event.touches[1]) /
this._getDistance(this._baseTouches[0], this._baseTouches[1])
);
}
protected _getCenter(event: TouchEvent): { x: number; y: number } {
return {
x: event.touches[0].clientX,
y: event.touches[0].clientY,
};
}
protected _getMovement(event: TouchEvent): { x: number; y: number } {
const prev = this.prevEvent.srcEvent as TouchEvent;
Iif (event.touches[0].identifier !== prev.touches[0].identifier) {
return {
x: 0,
y: 0,
};
}
return {
x: event.touches[0].clientX - prev.touches[0].clientX,
y: event.touches[0].clientY - prev.touches[0].clientY,
};
}
}
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